http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59021
Bug ID: 59021
Summary: [4.9 regression] new vzeroupper instructions generated
with -mavx
Product: gcc
Version: 4.9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: ebotcazou at gcc dot gnu.org
Created attachment 31173
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=31173&action=edit
Testcase
It's not clear to me whether this is a real bug or not, but new vzeroupper
instructions started to be generated with -mavx very recently because of:
2013-11-04 Vladimir Makarov <vmaka...@redhat.com>
PR rtl-optimization/58968
* lra-spills.c (return_regno_p): New function.
(lra_final_code_change): Use it.
For the attached testcase compiled with -O2 -mavx:
--- t.s.0 2013-11-06 12:17:49.080691443 +0100
+++ t.s 2013-11-06 12:17:55.005691730 +0100
@@ -23,12 +23,14 @@
call foo
testl %eax, %eax
jne .L6
+ vzeroupper
leave
.cfi_remember_state
.cfi_def_cfa 7, 8
ret
.L6:
.cfi_restore_state
+ vzeroupper
call abort
.cfi_endproc
.LFE0:
